1. Field
Embodiments of the invention relate to a compensation film, an optical film and a display device including the compensation film or the optical film.
2. Description of the Related Art
A flat panel display may be classified into a light-emitting display device that emits light by itself and a non-emissive display device that includes a separate light source and a compensation film such as a retardation film is generally employed for improving the image quality thereof.
In a light emitting display device, for example, an organic light emitting diode (“OLED”) display, the visibility and the contrast ratio may be deteriorated by reflection of the exterior light caused by a metal such as an electrode. To reduce the deterioration in the visibility and the contrast ratio, the linear polarized light is shifted into circularly polarized light using a polarizer and a compensation film, such that reflection of the external light by the OLED display and leakage thereof to the outside may be effectively prevented.
To reduce the reflection of the exterior light, the liquid crystal display (“LCD”), which is a non-emissive display device, changes the linear polarized light into the circularly polarized light to improve the image quality according to the type of the device such as a transparent type, a transflective type or a reflective type, for example.
However, a conventional compensation film is strongly dependent upon the wavelength to the incident light, so such a compensation film may effectively operate for light having a certain wavelength, but the effect thereof may be deteriorated for other wavelengths. In addition, a conventional compensation film may have strong viewing angle dependency.